Automatic circuit-breaker.



No. 806,666. PATENTED DEC. 5, 1905. B. M. HEWLETT.

AUTOMATIG CIRCUIT BREAKER.

APPLICATION FILED 00'1.11,189'T.

2 BIIEETS-SHEET 1.

I R p D E. M. HEWLETT! PATBNTED DEC. 5, 1905.

AUTOMATIC CIRCUIT BREAKER APPLIUATION FILED 0GT.11,1897.

2 SHEETS-SHEET 2.

W ionesses.

E dward NLHew ebb UNITED STATES PATENT OFFICE.

EDINARD M. HEWLETT, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

AUTOMATIC CIRCUIT-BREAKER.

Specification of Letters Patent.

Patented Dec. 5, 1905.

Application filed October 11, 1897. Serial No. 654,789-

To all 1077,0112 it may concern:

Be it known that I, EDWARD M. HEWLETT, a citizen of the United States, residing at Schenectady, in the county of Schenectady, State of New York, have invented certain new and useful Improvements in Automatic Circuit-Breakers, of which the following is a specification. I

The present invention has for its object to provide a double-pole circuit-breaker so arranged that a ground .on either of the mains or an overload on the system will automatically interrupt the circuit of both mains.

In the accompanying drawings, Figure 1 is a sectional view of my improved breaker, taken on line 1 1 of Fig. 2. Fig. 2 is a plan view of the breaker. Fig. 3 is a diagram of connections. Fig. 4 is a perspective view oi a circuit-breaker embodying my improvements. Fig. 5 is aplanview of oneside of the magnetic circuit. Fig. 6 is a side elevation of one of the cores and its pole-pieces, and Fig. 7 is an end view of the operating-magnets.

Mounted on an insulating-base A are magnets B and C, acting together to form a blowout magnet and provided, respectively, with enlarged pole-pieces B and C, separated from each other by an air-space. Each magnet is provided with an enlarged end B, resting on base A and forming a support for the core of the energizing-coil. Extending parallel with the enlarged end B is a rib B", which is expanded in a plane at right angles to that of the enlarged end to form a polepiece. Formed integral with the pole-pieces are feet B secured to base A for supporting the outer end of the pole-pieces. The polepieces are clamped together by non-magnetic bolts II. The latter also serve to hold the arc-restraining chute E in place. Energizingcoils l3 and C are provided for the magnets and connected, respectively, with bindingposts Q Q and each included in a different circuit-main. Secured to the upper end of the magnet-cores by screws are pole-pieces B C. These are adapted to attract armature D of the tripping device.

Located between the poles of the magnets is an arc-restraining chute E, made of insulating material and provided with a central partition E, arranged to separate the two sets of contacts F and G. The latter are arranged to make and break the circuit of mains a and l). Extending at right angles to the central partition E and side walls E are pieces E so arranged that they diverge as they extend beyond the switch-contacts, thus permitting the gas formed by the are at the contacts to expand as it passes outward. The working parts of the breaker are protected from injury due to arcs and molten metal by a piece of insulation E", extending beyond the chutes on all sides.

Secured to the side walls and extending at right angles thereto are pieces of insulation I and I, upon which are mounted four binding-posts, two for each main. The contactbrushes are also mounted on the insulating pieces I and I and in direct electrical connection with the binding-posts. Each brush consists of an L-shaped tip (1, supported by a thin strip of spring metal 6 and provided with a laminated conductorf to increase the conductivity. Stops g are provided to limit the movement of the brushes.

The shaft J is provided with an operatinghandle K and also with two contact carrying-arms L at their outer end, adapted to establish connection between the stationary brushes. The hub of the handle is provided with a projection J arranged to bear against spring-latch M, being shod with a steel wearing-shoe at the point of engagement, and hold the switch in its closed position against the action of spiral spring a, surrounding shaft J. A second projection J is also formed on the hub. When the switch is released and flies open under the action of spiral spring a, projection J 2 strikes against pin O and limits the movement of the switch.

Armature D of the tripping device has two extensions D, the. are sleeved upon shai t D The latter is mounted in suitable supports carried by the upper end of the magnets. To the upper side of armature D is secured an arm P, the free end of which passes through a slot in the end of a leaf-spring, which carries the detent M, arranged to'raise the spring latch away from projection J and release the switch-handle. To the armature is secured a tension device R, comprising a number of turns of wire and ascrew-threaded rod R with nuts for adjusting the tension of the spring.

In Fig. 3 is shown a diagram of connec- 5 tions, in which S represents the generator; Q and Q, the bindin -posts; 2 and C the blow-out-magnet coils, also acting as tripping-coils, and F and G switch-contacts in mains a and I).

It will be seen that a separate switch is provided for each main, each having a sepa rate tripping-coil, but acting on a common tripping device.

When the circuits are in their normal con- I 5 dition and an overload occurs, coils B and 2 5 suming that a circuit-breaker of ordinary co-nstruct1on having a smgle tripping-coil is employed on a system where a ground exists between the c1rcu1t-breaker and the generator on one mam and a second ground occurs on a difl'erent main beyond the breaker,

which shunts the tripping-coil, the breaker will fail to open. If, however, the breaker is provided with a separate tripping-coil for each main acting on a common tripping device,

the breaker will open, for one coil is always in readiness to act.

hat I claim as new, and desire to secure by Letters Patent of the United States, is

1. The combination with a pluralityoi' cir- 4o cuit-mains, of a circuit-breaker comprising a plurality of coils connected severally in said mains, a tripping device controlled by any of said coils, a magnetic blow-out common to all the coils, independent break-points for each main, and separate blow-out chutes for the several break-points.

2. In a switch or circuitbreaker, a blowout magnet comprising a plurality of magnetically-insulated pole-pieces, independent cores connected thereto, a separate magnetcoil for each of said cores, a plurality of break-points, and independent arc-chutes for the several break-points.-

3. The combination with a plurality of circuit-mains, of a circuit-breaker arranged to make and break the circuit of more than one main, comprising fixed and moving contacts for each main, sep a1 ate arc-restraining chutes for each set of contacts, a blow-out magnet energized by the current flowing in the different mains, and a common tripping device for the mains.

4. The combination with a plurality of circuit-mains, of a circuit-breaker comprising magnetically-insulated pole pieces operating together to form a blow-out magnet, coils for the pole-pieces included in the diflerent circuit-mains, brushes and contacts for m aking and breaking the circuit of each main, an insulating-chute for each set of brushes and contacts, an operating-handle, and a common tripping device controlled by the current flowing in the magnet-coils.

5. A circuit-breaker comprising two coils connected in diflerent sides of a circuit, a pair of contacts for each coil and corresponding bridging contacts, and a magnetic field common to and inclosing said contacts.

In witness whereof I have hereunto set my hand this 6th day of October, 1897.

EDWARD M. HEVLETT.

Witnesses B. B. HULL, E. W. CADY. 

